Gas phase polymerization process

Abstract

The present invention relates to a process for continuous gas phase polymerization of olefin(s) in a reactor containing a fluidized bed, consisting of a cylinder with a vertical side wall and of a desurging or disengagement chamber ( 3 ) mounted above the said cylinder, characterized in that the fluidized bed occupies at least all of the cylinder with a vertical side wall of the reactor.

We claim:  
     
       1. Process for gas phase polymerization of one or more monomers in a fluidized bed reactor, which reactor includes a cylinder above which is mounted a disengagement vessel, wherein the reaction gas mixture passes through the cylinder with an upward speed from 0.3 to 1 m/s, and wherein the fluidized bed occupies at least all of the cylinder. 
     
     
       2. Process according to  claim 1 , wherein the reaction gas mixture passes through the reactor with an upward speed from 0.4 to 0.8 m/s. 
     
     
       3. Process according to  claim 1 , wherein the fluidized bed occupies at least partially the disengagement vessel. 
     
     
       4. Process according to  claim 1 , in which one or more olefinic monomers selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene and 1-octene are polymerized. 
     
     
       5. Process for continuous gas phase polymerization of olefin(s) in a reactor containing a fluidized bed, which reactor includes a cylinder with a vertical side wall and a disengagement chamber mounted above the cylinder and in communication therewith, said process comprising operating at an absolute pressure higher than the atmospheric pressure, continuously or intermittently introducing a catalyst into the reactor, continuously passing a reaction gas mixture containing one or more olefin monomers through the fluidized bed in an upward stream at an upward speed ranging from 0.3 to 1 m/s, removing the heat of polymerization by withdrawing and cooling the gaseous stream from the reactor, recycling said cooled gaseous stream back to the reactor, and removing polymer produced, wherein the fluidized bed of the reactor occupies at least all of the cylinder of the reactor. 
     
     
       6. Process according to  claim 5 , wherein the reaction gas mixture passes through the reactor with an upward speed from 0.4 to 0.8 m/s. 
     
     
       7. Process according to  claim 5 , wherein the fluidized bed occupies at least partially the disengagement vessel. 
     
     
       8. Process according to  claim 5 , in which one or more olefinic monomers selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1pentene, 1-hexene and 1-octene are polymerized. 
     
     
       9. Process according to any one of claims  1  and  5 , in which polymerization takes place with a polymer output rate higher than 50 kg/h/m 3 . 
     
     
       10. Process according to  claim 9 , in which polymerization takes place with a polymer output rate higher than 60 kg/h/m 3 . 
     
     
       11. Process according to  claim 10 , in which polymerization takes place with a polymer output rate higher than 70 kg/h/m 3 . 
     
     
       12. Process according to any one of claims  1  and  5 , wherein the fluidized bed occupies more than 5% of the total volume of the disengagement vessel. 
     
     
       13. Process according to  claim 12 , wherein the fluidized bed occupies more than 10% of the total volume of the disengagement vessel. 
     
     
       14. Process according to  claim 13 , wherein the fluidized bed occupies more than 15% of the total volume of the disengagement vessel. 
     
     
       15. Process according to any one of claims  1  and  5 , wherein the fluidized bed occupies less than 70% of the total volume of the disengagement vessel. 
     
     
       16. Process according to  claim 15 , wherein the fluidized bed occupies less than 50% of the total volume of the disengagement vessel. 
     
     
       17. Process according to  claim 16 , wherein the fluidized bed occupies less than 30% of the total volume of the disengagement vessel.